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Search Results: 1 - 10 of 153116 matches for " Christian K?hler "
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A Functional Driver Analyzing Concept
Tobias Islinger,Thorsten Khler,Christian Wolff
Advances in Human-Computer Interaction , 2011, DOI: 10.1155/2011/413964
Abstract: It is evident that a lot of accidents occur because of drowsiness or inattentiveness of the driver. The logical consequence is that we have to find methods to better analyze the driver. A lot of research has been spent on camera-based systems which focus on the driver's eye gaze or his head movement. But there are few systems that provide camera-free driver analyzing. This is the main goal of the work presented here which is structured in three phases, with the operational goal of having a working driver analyzer implemented in a car. The main question is: is it possible to make statements concerning the driver and his state by using vehicle data from the CAN Bus only? This paper describes the current state of driver analyzing, our overall system architecture, as well as future work. At the moment, we focus on detecting the driving style of a person. 1. Introduction Driver analysis (DA) has been an active field of research for years. For example, [1] published an article about driver monitoring already in 2005. Among others, DA can be divided in the following subtopics: driver monitoring, driving style analysis, and merging vehicle data to derive conclusions concerning the driver (The word driver means both, female as well as male drivers. This is also relevant for words like “his” or “him” which reflect also both, female as well as male persons.) and his environment. For our research work, we focus on the following aspects. (i)How can the state of the driver be detected without using a camera or realtime biosensor data like a electrocardiogram (ecd)? (ii)How can we support the driver, depending on his actual driving situation, based on the results of the driver state detection? Driver monitoring is usually performed by cameras installed in the car for detecting the driver's behavior or state, mostly by using infrared cameras ([2, 3], or [1]). There are also first results for noncamera based research on driver analysis: By analyzing analog speed graphs, Rygula [4] makes conclusions about the driving style, speed profile and, depending on driving time and course, aggressiveness of the driver. Therefore, he evaluated ten analog speed graphs for two drivers by comparing their speed profile, their profile referring to the distance, or referring to route and direction. Rygula states that “Even a brake of 45 minutes reduce aggressivity of driving style” ([4, page 79]). A different approach is the research on context recognition in vehicles and the development of a driver model. Ferscha and Riener [5] describe this process of in-car context recognition and
The Drosophila SH2B Family Adaptor Lnk Acts in Parallel to Chico in the Insulin Signaling Pathway
Christian Werz,Katja Khler,Ernst Hafen,Hugo Stocker
PLOS Genetics , 2009, DOI: 10.1371/journal.pgen.1000596
Abstract: Insulin/insulin-like growth factor signaling (IIS) plays a pivotal role in the regulation of growth at the cellular and the organismal level during animal development. Flies with impaired IIS are developmentally delayed and small due to fewer and smaller cells. In the search for new growth-promoting genes, we identified mutations in the gene encoding Lnk, the single fly member of the SH2B family of adaptor molecules. Flies lacking lnk function are viable but severely reduced in size. Furthermore, lnk mutants display phenotypes reminiscent of reduced IIS, such as developmental delay, female sterility, and accumulation of lipids. Genetic epistasis analysis places lnk downstream of the insulin receptor (InR) and upstream of phosphoinositide 3-kinase (PI3K) in the IIS cascade, at the same level as chico (encoding the single fly insulin receptor substrate [IRS] homolog). Both chico and lnk mutant larvae display a similar reduction in IIS activity as judged by the localization of a PIP3 reporter and the phosphorylation of protein kinase B (PKB). Furthermore, chico; lnk double mutants are synthetically lethal, suggesting that Chico and Lnk fulfill independent but partially redundant functions in the activation of PI3K upon InR stimulation.
Sensitive and reliable detection of Kit point mutation Asp 816 to Val in pathological material
Christian Khler, Sabine Didlaukat, Alfred C Feller, Hartmut Merz
Diagnostic Pathology , 2007, DOI: 10.1186/1746-1596-2-37
Abstract: The Kit point mutation Asp 816 to Val is heterozygous which means a problem in detection by PCR because the wild-type allele is also amplified and the number of cells which bear the point mutation is in most of the cases low. Most PCR protocols use probes to block the wild-type allele during amplification with more or less satisfying result. This is why point-mutated forward primers were designed and tested for efficiency in amplification of the mutated allele.One primer combination (A) fits the most for the introduced PCR assay. It was able just to amplify the mutated allele with high specificity from different patient's materials (FFPE or blood) of varying quality and quantity. Moreover, the sensitivity for this assay was convincing because 10 ng of DNA which bears the point mutation could be detected in a total volume of 200 ng of DNA.The PCR assay is able to deal with different materials (blood and FFPE) this means quality and quantity of DNA and can be used for high-througput screening because of its robustness. Moreover, the method is easy-to-use, not labour-intensive, and easy to realise in a standard laboratory.1,000 to 8,000 incidences of human mastocytosis are reported every year in the US [1]. Human mastocytosis is characterised by accumulation of mast cells in different organs. It is a heterogenous group of disorders which can be divided into the categories cutaneous mastocytosis (CM) and systemic mastocytosis (SM) which is commonly seen in adults by histological lesions in the bone marrow and other non-cutaneous organs [2,3]. SM can be further divided into the categories indolent systemic mastocytosis (ISM), SM with an associated clonal hematologic non-mast cell lineage disease (AHNMD), aggressive sytemic mastocytosis (ASM), and mast cell leukemia (MCL). ISM is the most common form which involves skin, bone marrow, and GI tract with good prognosis for the patient. First relations between mastocytosis and activating mutations in the receptor tyrosine kin
Emotion recognition in pictures of facial affect: Is there a difference between forensic and non-forensic patients with schizophrenia?
Wiebke Wolfkühler,Karina Majorek,Cumhur Tas,Christian Küper
The European Journal of Psychiatry , 2012,
Abstract: Background and Objectives: Abundant research has demonstrated that patients with schizophrenia have difficulties in recognizing the emotional content in facial expressions. However, there is a paucity of studies on emotion recognition in schizophrenia patients with a history of violent behavior compared to patients without a criminal record. Methods: Emotion recognition skills were examined in thirty-three forensic patients with schizophrenia. In addition, executive function and psychopathology was assessed. Results were compared to a group of 38 schizophrenia patients in regular psychiatric care and to a healthy control group. Results: Both patient groups performed more poorly on almost all tasks compared to controls. However, in the forensic group the recognition of the expression of disgust was preserved. When the excitement factor of the Positive and Negative Syndrome Scale was co-varied out, forensic patients outperformed the non-forensic patient group on emotion recognition across modalities. Conclusions: The superior recognition of disgust could be uniquely associated with delinquent behavior.
Surfactant-driven flow transitions in evaporating droplets
Alvaro Marin,Robert Liepelt,Massimiliano Rossi,Christian J. Khler
Physics , 2015, DOI: 10.1039/C5SM02354H
Abstract: An evaporating droplet is a dynamic system in which flow is spontaneously generated to minimize the surface energy, dragging particles to the borders and ultimately resulting in the so-called "coffee-stain effect". The situation becomes more complex at the droplet's surface, where surface tension gradients of different nature can compete with each other yielding different scenarios. With careful experiments and with the aid of 3D particle tracking techniques, we are able to show that different types of surfactants turn the droplet's surface either rigid or elastic, which alters the evaporating fluid flow, either enhancing the classical coffee-stain effect or leading to a total flow inversion. Our measurements lead to unprecedented and detailed measurements of the surface tension difference along an evaporating droplet's surface with good temporal and spatial resolution.
Quorum Sensing Inhibition Selects for Virulence and Cooperation in Pseudomonas aeruginosa
Thilo Khler,Gabriel G. Perron,Angus Buckling,Christian van Delden
PLOS Pathogens , 2010, DOI: 10.1371/journal.ppat.1000883
Abstract: With the rising development of bacterial resistance the search for new medical treatments beyond conventional antimicrobials has become a key aim of public health research. Possible innovative strategies include the inhibition of bacterial virulence. However, consideration must be given to the evolutionary and environmental consequences of such new interventions. Virulence and cooperative social behaviour of the bacterium Pseudomonas aeruginosa rely on the quorum-sensing (QS) controlled production of extracellular products (public goods). Hence QS is an attractive target for anti-virulence interventions. During colonization, non-cooperating (and hence less virulent) P. aeruginosa QS-mutants, benefiting from public goods provided by wild type isolates, naturally increase in frequency providing a relative protection from invasive infection. We hypothesized that inhibition of QS-mediated gene expression removes this growth advantage and selection of less virulent QS-mutants, and maintains the predominance of more virulent QS-wild type bacteria. We addressed this possibility in a placebo-controlled trial investigating the anti-QS properties of azithromycin, a macrolide antibiotic devoid of bactericidal activity on P. aeruginosa, but interfering with QS, in intubated patients colonized by P. aeruginosa. In the absence of azithromycin, non-cooperating (and hence less virulent) lasR (QS)-mutants increased in frequency over time. Azithromycin significantly reduced QS-gene expression measured directly in tracheal aspirates. Concomitantly the advantage of lasR-mutants was lost and virulent wild-type isolates predominated during azithromycin treatment. We confirmed these results in vitro with fitness and invasion experiments. Azithromycin reduced growth rate of the wild-type, but not of the lasR-mutant. Furthermore, the lasR-mutant efficiently invaded wild-type populations in the absence, but not in the presence of azithromycin. These in vivo and in vitro results demonstrate that anti-virulence interventions based on QS-blockade diminish natural selection towards reduced virulence and therefore may increase the prevalence of more virulent genotypes in the Hospital environment. More generally, the impact of intervention on the evolution of virulence of pathogenic bacteria should be assessed. Trial Registration: ClinicalTrials.gov NCT00610623
Autoinducer production and quorum-sensing dependent phenotypes of Pseudomonas aeruginosa vary according to isolation site during colonization of intubated patients
Sabine Favre-Bonté, Eric Chamot, Thilo Khler, Jacques-A Romand, Christian van Delden
BMC Microbiology , 2007, DOI: 10.1186/1471-2180-7-33
Abstract: We wondered whether QS is active during colonization of intubated patients, and whether P. aeruginosa isolates growing inside the biofilm covering the intubation devices and those resident in the lungs of colonized patients differ in their QS-dependent phenotypes. We collected the intubation devices of eight patients colonized by P. aeruginosa. We detected 3-oxo-C12-HSL on eight, and C4-HSL on six of these devices. In three of these patients we also obtained P. aeruginosa isolates from tracheal aspirates at the time of extubation (n = 18), as well as isolates from the intubation devices (n = 25). We genotyped these isolates, quantified their AIs production, and determined three QS-dependent phenotypes (adherence capacity, biofilm and elastase production). The production of 3-oxo-C12-HSL was consistently increased for isolates from the intubation devices, whereas the production of C4-HSL was significantly higher for isolates from tracheal aspirates. Isolates from tracheal aspirates produced significantly higher amounts of elastase but less biofilm, and had a marginally reduced adhesion capacity than isolates from the intubation devices. Levels of 3-oxo-C12-HSL and elastase production correlated statistically for tracheal intubation isolates, whereas levels of 3-oxo-C12-HSL production and adhesion ability, as well as biofilm production, correlated weakly amongst intubation device isolates.Our findings demonstrate that autoinducers are produced during the colonization of intubated patients by P. aeruginosa. The microenvironment, in which P. aeruginosa grows, may select for bacteria with different capacities to produce autoinducers and certain QS-dependent phenotypes. QS-inhibition might therefore affect differently isolates growing inside the biofilm covering intubation devices and those resident in the lungs.Pseudomonas aeruginosa is an opportunistic pathogen implicated in a wide variety of infections, particularly in burn victims, cancer patients and cystic fibrosis
Primary sarcoma of the pancreas, a rare histopathological entity. A case report with review of literature
Peter Ambe, Christian Kautz, Shawqi Shadouh, Silvia Heggemann, Lothar Köhler
World Journal of Surgical Oncology , 2011, DOI: 10.1186/1477-7819-9-85
Abstract: the case of a 52 year old patient presenting with jaundice is presented and the available literature was reviewed.primary pancreatic sarcomas are extremely rare. Pancreatic sarcomas are more aggressive than other pancreatic neoplasms.primary sarcomas of the pancreas are extremely rare, are aggressive and are associated with very poor prognosis.Sarcomas represent a relatively rare malignant entity. Primary sarcomas of the pancreas are even rarer. Amongst pancreatic sarcomas, leiomyosarcomas have been most commonly reported. A review of the literature reveals seven cases of carcinosarcoma. We report a case of epitheloid carcinosarcoma in a young male patient presenting with pancreatitis and jaundice.A 52 year old male with a history of chronic alcohol consumption was admitted in the medical department of our community hospital with an acute onset of upper abdominal pain, nausea and vomiting. The diagnostic workup revealed elevated amylase and lipase of 1012U/l and 1160U/l respectively. A swollen edematous pancreas caput and gallbladder stones were evident on upper abdominal ultrasound. At the time of admission, an endoscopic retrograde cholangio-pancreaticography (ERCP) was performed. The common bile duct however could not be visualized. ERCP was repeated after three days with papillotomy. A narrow common bile duct without stones or stenosis was visualized [Figure 1].The patient recovered fully and was discharged after 8 days. One month after discharge the patient was readmitted with right upper quadrant pain and jaundice. The routine workup revealed elevated liver enzymes and bilirubin (total bilirubin: 10.78 mg/dl, direct bilirubin 9.86 mg/dl, indirect bilirubin:0.92 mg/dl, alkaline phosphatase: 337.64U/l). Cholecystitis was evident on upper abdominal sonography. Choledocholithiasis was present on ERCP, papillotomy and stone extraction were uneventful. Cholecystectomy was indicated.Laparoscopic cholecystectomy was performed. During laparoscopy the main bile duct app
QsrO a Novel Regulator of Quorum-Sensing and Virulence in Pseudomonas aeruginosa
Thilo Khler, Hajer Ouertatani-Sakouhi, Pierre Cosson, Christian van Delden
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087814
Abstract: In Pseudomonas aeruginosa, the production of many secreted virulence factors is controlled by a quorum-sensing (QS) circuit, constituted of transcriptional activators (LasR, RhlR, PqsR) and their cognate signaling molecules (3-oxo-C12-HSL, C4-HSL, PQS). QS is a cooperative behavior that is beneficial to a population but can be exploited by “QS-cheaters”, individuals which do not respond to the QS-signal, but can use public goods produced by QS-cooperators. In order to identify QS-deficient clones we designed a genetic screening based on a lasB-lacZ fusion. We isolated one clone (PT1617) deficient in QS-dependent gene expression and virulence factor production despite wild type lasR, rhlR and pqsR alleles. Whole genome sequencing of PT1617 revealed a 3,552 bp deletion encompassing ORFs PA2228-PA2229-PA2230 and the pslA gene. However, complementation of PT1617 by plasmid-encoded copies of these ORFs, did not restore QS. Unexpectedly, gene expression levels of ORFs PA2228, PA2227 (vqsM) and PA2222, located adjacent to the deletion, were 10 to 100 fold higher in mutant PT1617 than in PAO1. When expressed from a constitutive promoter on a plasmid, PA2226, alone was found to be sufficient to confer a QS-negative phenotype on PAO1 as well as on PA14. Co-expression of PA2226 and PA2225 in PAO1 further prevented induction of the type III secretion system. In summary, we have identified a novel genetic locus including ORF2226 termed qsrO (QS-repressing ORF), capable of down-regulating all three known QS-systems in P. aeruginosa.
Three-dimensional phenomena in microbubble acoustic streaming
Alvaro Marin,Massimiliano Rossi,Bhargav Rallabandi,Cheng Wang,Sascha Hilgenfeldt,Christian J. Khler
Physics , 2015,
Abstract: Ultrasound-driven oscillating micro-bubbles have been used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting and manipulation of microparticles. A common configuration consists on side-bubbles, created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration consists of acoustically excited bubbles with a semi-cylindrical shape that generate significant streaming flow. Due to the geometry of the channels, such flows have been generally considered as quasi two-dimensional. Similar assumptions are often made in many other microfluidic systems based on \emph{flat} micro-channels. However, in this paper we show that microparticle trajectories actually present a much richer behavior, with particularly strong out-of-plane dynamics in regions close to the microbubble interface. Using Astigmatism Particle Tracking Velocimetry, we reveal that the apparent planar streamlines are actually projections of a \emph{streamsurface} with a pseudo-toroidal shape. We therefore show that acoustic streaming cannot generally be assumed as a two-dimensional phenomenon in confined systems. The results have crucial consequences for most of the applications involving acoustic streaming as particle trapping, sorting and mixing.
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